The present invention relates to an optical pickup for reproducing data on a disk such as a compact disk (CD) and a laser disk (LD), and for producing a focus error signal and a tracking error signal for focusing and tracking the pickup.
FIG. 11 shows a conventional optical pickup. The optical pickup comprises a holder 1 having a coil 2 for focusing and a coil 2a for tracking, a pair of supporting plates 9 and 9a, and print circuit boards 6 and 6a secure to the supporting plates 9 and 9a. The holder has an optical system 1a. The holder 1 is suspended from the print circuit board 6 and 6a by four conductive wires 5. A pair of yokes 4 each having a magnet 3 are mounted on the supporting plates 9 and 9a, respectively. The holder 1 is disposed between the yokes 4 so as to oppose the coil 2 and 2a to the yokes, respectively. The holder 1 has a plurality of elements which are connected to a circuit substrate 8 through a flexible wiring plate 7. The flexible wiring plate 7 is curved at a central portion thereof for connecting the holder to the circuit substrate 8. An exciting current is supplied to the coils 2 and 2a, through the conductive wires 5 for moving the holder 1 in the focusing direction and the tracking direction.
In such a device, when the holder 1 is moved in the focusing direction, the flexible wiring plate 7 is twisted at a central portion thereof. Restoring force of the flexible wiring plate 7 causes the holder 1 to tilt with respect to the optical axis. Consequently, it is difficult to accurately focus the optical system of the pickup.